CORRESPONDENTE Daniela Brito de Jesus
THE EFFECT OF L2 PROFICIENCY ON THE DECLARATIVE AND PROCEDURAL MEMORY SYSTEMS OF BILINGUALS:
A PSYCHOLINGUISTIC STUDY
Dissertação submetida ao Programa de Pós-Graduação em Inglês da Universidade Federal de Santa Catarina para a obtenção do Grau de
Mestre em Letras
Orientadora: Profa. Dra. Mailce Borges Mota
Florianópolis 2012
Jesus, Daniela Brito de
The effect of L2 proficiency on the declarative and procedural memory systems of bilinguals: a
psycholinguistic study [dissertação] / Daniela Brito de Jesus ; orientadora, Mailce Borges Mota - Florianópolis, SC, 2012.
108 p. ; 21cm
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em Letras/Inglês e Literatura Correspondente. Inclui referências
1. Letras/Inglês e Literatura Correspondente. 2. Sistemas de memória de longo prazo. 3. Proficiência em L2. 4. Desempenho. 5. Bilinguismo. I. Mota, Mailce Borges . II. Universidade Federal de Santa Catarina. Programa de Pós-Graduação em Letras/Inglês e Literatura Correspondente. III. Título.
bilinguals: a psycholinguistic study”, foi julgada adequada e aprovada em sua forma final, pelo Programa de Pós-Graduação em Letras/Inglês e Literatura Correspondente, da Universidade Federal de Santa Catarina,
para fins de obtenção do grau de MESTRE EM LETRAS
Área de concentração: Inglês e Literatura Correspondente Opção: Língua Inglesa e Linguística Aplicada
__________________________________ Prof.ª Dr.ª Susana Bornéo Funck
Coordenadora do Curso BANCA EXAMINADORA:
__________________________________ Prof.ª Dr.ª Mailce Borges Mota
Orientadora e Presidente (UFSC)
_________________________________ Prof.ª Dr.ª Adja Balbino de Amorim Barbieri Durão (UFSC)
__________________________________ Prof. Dr. Augusto Buchweitz (PUC/RS)
__________________________________ Prof. Dr. Celso Henrique Soufen
Tumolo
(UFSC) Florianópolis, 28 de setembro de 2012.
Such an achievement like this would never be possible without the contribution and support of many others. With all my gratitude I thank each and all of you.
My advisor Dr. Mailce Borges Mota, for all the guidance and support throughout these years. You have been such an example of honesty and academic excellence to me. Thank you for contributing so much to my education, Mailce.
The Language and Cognitive Processes Laboratory (LabLing) for the financial support and all infra-structure.
The Graduate Program in English (PPGI) staff and faculty for all the support. João Carlos da Silva and Sirlei Zanette, for being so welcoming, and also each and all professors who have shared their knowledge with me both in undergraduate and graduate times.
CAPES and the Brazilian Ministry of Education, for the 2-year financial support.
The members of the examining committee, Dr. Augusto Buchweitz, Dr. Adja Balbino Durão and Dr. Celso Tumolo, for having agreed to read and evaluate my work and for providing comments and suggestions.
All those who agreed to participate in the pilot and the current study: friends, colleagues, classmates, students and ex-students, and in loving memory of my ex-student Jenifer Fernandes, a 20-year-old Psychology student who was interested in cognitive psychology as much as I am.
My colleagues and dear friends at PPGI, for the many moments of learning, discussing and laughing together, especially Mariana Perrino, Laura Mesquita, Martha Julia Martins, Sílvia Barros, Marina Martins, Marcelo Kremer, Márcia Kawamoto, Renata Gomes, Lívia Paschoal, Andreana Marchi and Pâmela Toassi, ‘the elegant people’. (Pam, thanks for exchanging so many e-mails and providing me with help and encouragement in this final part!)
My PPGLg fellows Gustavo Estivalét, for teaching me how to deal with the software and helping me program the experiments, and Igor Gadioli, for our great discussions and talks and for his great sense of humor.
Fabíola and Silmara da Silva, Cyntia Bailer, Caroline Roberto, Lisiane Fagundes, Tatiana Rondón, Keith Araújo, Josiane Teixeira and Cristiane de Lima. You bright up my life with your affection and motivation.
Ane Girondi, for sharing many moments of true friendship and helping me format the final version of this thesis.
Laércio and Carlos Carvalho, for their calm words and for teaching me great lessons of hope, wisdom and patience.
André Luis, my sweet companion, for his love, serenity and unconditional support.
My family, specially my parents Daniel (in memoriam) and Maria Miralva, for the gift of life, lots of love and the uncountable words of motivation and advice.
And finally God and His angels and mentors, for providing me strength and clarity throughout this path.
THE EFFECT OF L2 PROFICIENCY ON THE DECLARATIVE AND PROCEDURAL MEMORY SYSTEMS OF BILINGUALS:
A PSYCHOLINGUISTIC STUDY Daniela Brito de Jesus
Universidade Federal de Santa Catarina 2012
Advisor: Mailce Borges Mota
Memory is one of the mental processes that compose human cognition. It is one of the fundamental parts of cognitive processing, which also includes attention, perception, reasoning, and language. It is through these functions that humans are capable of interacting with other human beings and with the world. For bilinguals, this interaction takes place through the knowledge and use of at least two languages, which involves cognitive and linguistic processes that are systematically different from those engaged in monolingual language use (Bialystok, 2010). In this sense, being bilingual entails the management and appropriate development of at least two language systems, in which skills of mental management should apply to aspects of cognition such as attention, conflict resolution, and executive control (Bialystok, Craig, Green & Gollan, 2009). Previous research has demonstrated that bilingualism seems to bring advantages to certain cognitive abilities, including executive functioning and working memory (Bialystok, Craik & Luk, 2008). Based on the assumptions presented above, the current study goes a step further to investigate whether bilingualism affects declarative and procedural memory systems positively. Forty young adult participants were divided into 3 groups: two experimental and one control group. The first experimental group consisted of 16 high L2 proficiency Portuguese-English bilinguals. The second experimental group consisted of 16 low L2 proficiency Portuguese-English bilinguals. The third group was the control group and consisted of 8 Brazilian Portuguese monolinguals. All participants were tested in four psycholinguistic tasks, designed in Brazilian Portuguese (L1), which aimed at assessing declarative and procedural memory. Prior to testing sessions, all participants were submitted to one of three types of proficiency test.
Cambridge ESOL ‘Preliminary English Test’ (PET). The control group of monolinguals performed the Mini Language English Test, designed for the purposes of the present study to control for their knowledge of English. In the psycholinguistic tasks, the dependent variables were reaction time (RT) and accuracy (ACC), and multiple comparisons were run for data from the three groups. Overall results showed that most of the comparisons between bilinguals and monolinguals favored bilinguals in the performance of memory tasks, especially those aimed at assessing declarative memory. For the comparisons between the high proficiency group, the low proficiency group, and monolinguals, in the linguistic tasks, there was a very significant difference in performance favoring the high proficiency group in relation to their low proficiency and monolingual counterparts, suggesting a positive effect of L2 proficiency on these tasks. For the comparisons between the same groups in the nonlinguistic tasks, there were also statistically significant differences for the high proficiency group overall performance. Taken together, the results of the present study indicate that a higher level of proficiency in an L2 seems to contribute to more accurate performance on declarative and procedural memory tasks. These results are discussed in light of the theoretical and empirical literature on human memory, bilingualism and language proficiency. Keywords: Long-term memory systems. L2 proficiency. Performance. Bilingualism.
Number of pages: 108 Number of words: 29070
RESUMO
O EFEITO DA PROFICIÊNCIA EM L2 NOS SISTEMAS DE MEMÓRIA DECLARATIVA E PROCEDURAL EM BILÍNGUES:
UM ESTUDO PSICOLINGUÍSTICO Daniela Brito de Jesus
Universidade Federal de Santa Catarina 2012
Orientadora: Mailce Borges Mota
A memória é um dos processos mentais que compõe a cognição humana. Ela é uma das partes fundamentais do processamento cognitivo, juntamente com a atenção, a percepção, o raciocínio e a linguagem. É através destas funções que os humanos são capazes de interagir com outros seres humanos e com o ambiente em que vivem. Para os bilíngues, esta interação ocorre através do conhecimento e do uso de, pelo menos, duas línguas, o que por sua vez envolve processos cognitivos e linguísticos que são sistematicamente diferentes daqueles empregados por monolíngues (Bialystok, 2010). Nesse sentido, ser bilíngue requer o gerenciamento e o desenvolvimento apropriado de dois sistemas linguísticos, nos quais as habilidades mentais de gerenciamento devem se estender a aspectos da cognição tais como a atenção, a resolução de conflitos e o controle executivo (Bialystok, Craig, Green & Gollan, 2009). Estudos recentes demonstraram que o bilinguismo parece trazer vantagens e contribuições a certas habilidades cognitivas, que incluem as funções executivas e a memória de trabalho (Bialystok, Craik & Luk, 2008). Com base na pesquisa sobre os efeitos do bilinguismo nas funções cognitivas, o presente estudo investiga se o bilinguismo afeta os sistemas de memória declarativa e procedural positivamente. Quarenta participantes jovens adultos foram divididos em três grupos: dois grupos experimentais e um grupo controle. Dezesseis participantes bilíngues do par linguístico português-inglês de alta proficiência em L2 compuseram o primeiro grupo experimental. O segundo grupo experimental foi composto por dezesseis participantes bilíngues do par linguístico português-inglês de baixa proficiência em L2. O terceiro grupo foi o grupo controle, composto por oito participantes monolíngues de Português brasileiro. Todos os participantes foram testados em quatro tarefas psicolinguísticas desenvolvidas em português brasileiro (L1) com o objetivo de avaliar os
sistemas de memória declarativa e procedural dessa população. Antes de serem submetidos às tarefas, os participantes foram submetidos a um de três tipos de testes de proficiência. Os bilíngues com baixa proficiência desempenharam o Cambridge ESOL ‘Key English Test’, enquanto os de alta proficiência desempenharam o Cambridge ESOL ‘Preliminary English Test’ (PET). O grupo controle de monolíngues desempenhou o Mini Teste de Linguagem em Inglês, desenvolvido para os fins do presente estudo com o objetivo específico de controlar o conhecimento em inglês desses participantes. Nas tarefas psicolinguísticas, as variáveis dependentes foram tempo de reação (RT) e acurácia (ACC). Comparações múltiplas foram realizadas nos dados obtidos dos três grupos. De maneira geral, os resultados mostraram que a maioria das comparações feitas entre bilíngues e monolíngues (considerando o tempo de resposta, o desvio padrão e a acurácia dos participantes em todas as tarefas) favoreceu os bilíngues no desempenho em tarefas de memória, especialmente naquelas destinadas à avaliação da memória declarativa. Para as comparações entre o grupo de alta proficiência, o de baixa proficiência e os monolíngues, nas tarefas linguísticas, houve uma diferença significativa no desempenho do grupo de alta proficiência, em relação aos grupos de baixa proficiência e os monolíngues, sugerindo um efeito positivo da proficiência em L2 nessas tarefas. Para as comparações entre os mesmos grupos nas tarefas não-linguísticas, diferenças significativas também foram encontradas no desempenho do grupo de alta proficiência. Todos esses resultados, de forma geral, indicam que a proficiência em L2 parece contribuir de forma positiva para um desempenho mais acurado em tarefas de memória declarativa e procedural. Esses resultados são discutidos à luz de estudos teóricos e empíricos sobre memória humana, bilinguismo e proficiência. Palavras-chave: Sistemas de memória de longo prazo. Proficiência em L2. Desempenho. Bilinguismo.
TABLE OF CONTENTS
1 INTRODUCTION ...23
1.1 PRELIMINARIES ...23
1.2 THE PRESENT STUDY ...26
1.3 SIGNIFICANCE OF THE STUDY ...27
1.4 ORGANIZATION OF THE THESIS ...27
2 REVIEW OF LITERATURE ...29
2.1 HUMAN MEMORY ...29
2.1.1 Episodic/ Semantic Memory Distinction ...34
2.1.2 Explicit/ Implicit Memory Distinction ...35
2.1.3 Declarative/ Procedural Memory Distinction ...38
2.2 BILINGUALISM ...42
2.2.1 Memory Systems in Bilinguals ...44
2.2.1.1 The Declarative/ Procedural Model ...46
2.3 LANGUAGE PROFICIENCY ...48 2.3.1 The Role of L2 proficiency in cognitive performance ...50 3 METHOD ...53 3.1 OBJECTIVES ...53 3.2 RESEARCH QUESTIONS ...53 3.3 HYPOTHESES ...55
3.4 GENERAL RESEARCH DESIGN ...55
3.5 PARTICIPANTS ...58
3.6 INSTRUMENTS OF DATA COLLECTION ...59
3.6.1 Consent Forms and Questionnaires ...59
3.6.2 Proficiency Tests and Mini Language Test ...60
3.6.3 Memory Tasks ...62
3.6.3.1 Assessment of Declarative Memory ...62
3.6.3.1.1 The Picture-Naming Task...62
3.6.3.1.2 The Picture-Recognition Task ...64
3.6.3.2 Assessment of Procedural Memory ...65
3.6.3.2.1 The Artificial Grammar Learning Task...65
3.6.3.2.2 The Alternating Serial Reaction Time Task ...67
3.7 PROCEDURES FOR DATA COLLECTION ...68
3.7.1 First Session - Bilinguals ...69
3.7.3 First Session - Monolinguals ...70
3.7.4 Second Session - Monolinguals ...70
3.8 DATA ANALYSIS ...70
3.9 PILOT STUDY ...71
4 RESULTS AND DISCUSSION ...73
4.1 DESCRIPTIVE ANALYSES ...73
4.2 INFERENTIAL ANALYSES ...81
4.3 READRESSING THE RESEARCH QUESTIONS ...89
5 FINAL REMARKS ...91
5.1 CONCLUSIONS ...91
5.2 LIMITATIONS OF THE STUDY AND SUGGESTIONS FOR FURTHER RESEARCH ...93
5.3 PEDAGOGICAL IMPLICATIONS ...93
REFERENCES ...95
LIST OF TABLES
Table 3.1 – The tasks ... 54 Table 3.2 – The proficiency/language groups ... 54 Table 3.3 – Data collection procedures for the experimental groups in a single session (Low and high) ... 56 Table 3.4 – Data collection procedures for the experimental groups in two sessions (Low and high) ... 57 Table 3.5 – Data collection procedures for the control group in a single session (Mono) ... 57 Table 3.6 – Data collection procedures for the control group in two sessions (Mono) ... 57 Table 4.1 – Descriptive statistics for the Picture Naming (PN) Task – Mean reaction time and accuracy by language groups (Bil and Mono) .. ... 74 Table 4.2 – Descriptive statistics for the Picture Naming (PN) Task - Mean reaction time and accuracy by proficiency groups (High and low) ... 75 Table 4.3 – Descriptive statistics for the Artificial Grammar Learning (AGL) Task - Mean reaction time and accuracy by language groups (Bil and mono) ... 76 Table 4.4 – Descriptive statistics for the Artificial Grammar Learning (AGL) Task - Mean reaction time and accuracy by proficiency groups (High and low) ... 77 Table 4.5 – Descriptive statistics for the Picture Recognition (PR) Task - Mean reaction time and accuracy by language groups (Bil and mono) ... ... 78 Table 4.6 – Descriptive statistics for the Picture Recognition (PR) Task - Mean reaction time and accuracy by proficiency groups (High and low) ... 78 Table 4.7 – Descriptive statistics for the Alternating Serial Reaction Time (ASRT) Task - Mean reaction time and accuracy by language groups (Bil and mono) ... 80 Table 4.8 – Descriptive statistics for the Alternating Serial Reaction Time (ASRT) Task - Mean reaction time and accuracy by proficiency groups (High and mono) ... 80 Table 4.9 – Shapiro-Wilk normality tests’ results for the different language/proficiency groups ... 82
Table 4.10 – RT and ACC comparison for the proficiency/language groups in the declarative memory tasks ... 83 Table 4.11 – RT and ACC comparison for the proficiency/language groups in the procedural memory tasks ... 84
LIST OF FIGURES
Figure 3.1 – Sample of a correct and an incorrect oral response on the Picture Naming (PN) Task ... 63 Figure 3.2 – Sample of a correct (real) and an incorrect (unreal) response on the Picture Recognition (PR) Task ... 64 Figure 3.3 – Illustration on some items used for the learning phase in the Artificial Grammar Learning (AGL) Task ... 66 Figure 3.4 – Illustration on the Serial Response Box used and the key(s) to press according to the position of each stimulus on the computer screen ... 68
LIST OF APPENDICES
APPENDIX A – Consent form ... 109
APPENDIX B – Language background questionnaire ...111
APPENDIX C – Task instructions for the PN Task ... 115
APPENDIX D– Task instructions for the PR Task ... 116
APPENDIX E – Task instructions for the AGL Task ... 117
APPENDIX F – Post-task questionnaire – AGL Task ... 120
APPENDIX G – Participants ... 122
APPENDIX H – Boxplot comparing the reaction time between the High, Low and Mono groups for the PN Task ... 126
APPENDIX I – Boxplot comparing the reaction time between the High, Low and Mono groups for the PR Task ... 127
APPENDIX J – Boxplot comparing the reaction time between the High, Low and Mono groups for the AGL Task ... 128
APPENDIX K – Boxplot comparing the reaction time between the High, Low and Mono groups for the ASRT Task ... 129
APPENDIX L – Bar graph comparing the scoring from the High, Low and Mono groups in the PN Task ... 130
APPENDIX M – Bar graph comparing the scoring from the High, Low and Mono groups in the PR Task ... 131
APPENDIX N – Bar graph comparing the scoring from the High, Low and Mono groups in the AGL Task ... 132
APPENDIX O – Bar graph comparing the scoring from the High, Low and Mono groups in the ASRT Task ... 133
LIST OF ABBREVIATIONS AND SYMBOLS PPGI – Programa de Pós-Graduação em Inglês/UFSC L1 – first language
L2 – second language AL – Applied Linguistics
SLA – Second Language Acquisition PN – Picture Naming Task
PR – Picture Recognition Task
AGL – Artificial Grammar Learning Task ASRT – Alternating Serial Reaction Time Task Bil – bilingual(s)
Mono – monolingual(s)
High – high (L2) proficiency bilinguals Low – low (L2) proficiency bilinguals N – number of participants
DP Model – Declarative Procedural Model of language
LabLing – Language and Cognitive Processes Laboratory/UFSC KET – Cambridge ESOL Examination ‘Key English Test’ PET – Cambridge ESOL Examination ‘Preliminary English Test’ CEFR – Common European Framework of Reference for Language ms - milliseconds
SRBOX – Serial Response Box RT – reaction time
ACC – accuracy SD - standard deviation
SPSS – Statistical Package for Social Science software M – mean
SD – standard deviation
CHAPTER I INTRODUCTION
1.1 Preliminaries
Memory is central to most aspects of human experience. We are who we are mostly because of what we learn and remember (Squire & Kandel, 2009). However, memory is much more than a record of personal experience: it allows us to become educated and to share what we have learned with other humans, through communication and, therefore, language (Squire & Kandel, 2009, p. 2). Within the several domains of cognitive psychology1 (e.g. attention and consciousness), memory and language are two particularly challenging aspects of human cognition (Eysenck & Keane, 2005).
During the past twenty years, many attempts to better understand the relationship between memory and language emerged in research (e.g. Gazzaniga, 2009; Paradis, 1994; 1995a; 1998; Ullman, 2001a; 2001b; 2001c; 2004). In 2009, I had the chance to read two book chapters published by Michael Ullman (2005; 2006) that referred to aspects of the neural bases of the mental lexicon (some sort of mental dictionary) and the mental grammar in first and second language (L1 and L2). In his 2005 chapter, he discusses a neurocognitive model of language, in an attempt to provide the knowledge base and empirical approaches of cognitive neuroscience to bear on the study of Second Language Acquisition (SLA) (Ullman, 2005). In the 2006 chapter, the author explores the biology of the brain and issues related to the study of the biology of language (Ullman, 2006). These chapters would provoke me to pursue further the literature in one of the theoretical frameworks adopted in Applied Linguistics (AL) research in Brazil: Cognitivism. This framework can be associated to some recent research which is in contact with neuroscience, specifically the neuroscience of language, and also to recent trends in cognitive science and psychology.
1 Cognitive Psychology is a psychological science which is interested in various mind and brain
related subfields such as cognition, the mental processes that underlie behavior, reasoning, and decision making (Eysenck & Keane, 2005).
Integrating issues of the cognitive science and SLA literature with psycholinguistics2 and cognitive psychology, the present study was designed to investigate the effect(s) of L2 proficiency on long-term memory systems from a psycholinguistic – behavioral – perspective. More specifically, the present investigation aims at exploring the declarative and procedural memory performance of bilinguals at two levels of L2 proficiency – low and high proficiency - on cognitive tasks in their first language (L1) – Brazilian Portuguese.
According to Gander and Gardiner (1981), the term cognition can be thought of as the act or process of obtaining knowledge, including perceiving, recognizing, reasoning and judging. Cognition involves thinking, knowing, remembering, categorizing and problem solving (Gander & Gardiner, 1981). It is the human capacity to acquire knowledge, since it deals with how our brain acquires, processes, interprets, memorizes and projects the information from the world we live in (Gander & Gardiner, 1981). In this sense, memory is one of the essential elements for human cognition.
Human cognition and mental processes are explored by cognitive psychology, which is a subdiscipline of psychology concerned with the acquisition, processing and storing of information. According to Ashcraft (1994), one possible approach towards the understanding of memory is cognitive psychology and the three assumptions that inform the field are (1) that mental processes exist, (2) that people are active information-processors, and (3) that mental processes and structures can be revealed by time and accuracy measures. The assumptions from cognitive psychology state that, by observing patterns of behavior, it will be possible to infer the “mental” events causing such behavior (Gregg, 1986 in Xhafaj 2006). Thus, considering that mental processes take time, one way to make inferences on the workings of the mind is by observing how long a given process takes to be completed (Ashcraft, 1994). Much mental effort is required to make use of central cognitive abilities such as attention, perception, thinking, reasoning, memory and language (Reed, 2007 in Kramer, 2011). Hence, from a cognitive perspective, the present study will address issues in SLA and bilingualism, and in the study of memory in first (L1) language, in a sample of Portuguese-English bilinguals at low and high L2 proficiency and of Brazilian Portuguese monolingual 2 According to Gleason and Ratner (1998), the field of psycholinguistics, or the psychology of
language, is concerned with discovering the psychological processes by which humans acquire and use language.
participants when performing memory tasks. One important issue in SLA, addressed in the current study concerns internal factors - that is, cognitive mechanisms which enable learners to extract information about the L2 from the input they receive (Ellis, 2008), and whether this amount of input (knowledge) possessed by learners in the L2 causes any effect on their long-term memory.
In the past decades, according to Mota (2011), SLA has been an active field of research. Studies in the area have dealt with the main issues discussed in the national and international scenario and have done so from a variety of conceptual approaches and research methodologies (p. 9). Given that SLA is a well-established area of research and is growing as a field of inquiry in Brazil, it is important to consider studies that cover themes in the contemporary research of the mechanisms and processes involved in the acquisition of a non-primary language (Mota, 2011). Thus, studies that address issues related to cognition and neurocognition of SLA bring solid contributions to recent trends in the field.
Recent studies in cognition in SLA and bilingualism have focused on the linguistic and cognitive benefits of bilingualism (e.g. Bialystok, 2001; Bialystok, 2004); this research has attempted to establish the nature of these benefits and the point at which they emerge (Babcock, Krawczyk & Scialabba, 2011). Results on the advantages of bilingualism vary greatly, indicating positive cognitive effects, especially in the areas of control processes and conflict resolution (e.g. Bialystok, 2007; Costa, Hernández, Costa-Faidella & Sebastian-Gallés, 2009; Luk, Sa & Bialystok, 2011). Over the past years, several studies (e.g. Bialystok, 2001; Bialystok, 2010; Bialystok & Craik, 2010; Bialystok, Craik & Luk, 2008a; Bialystok, Craik & Luk, 2008b; Bialystok, Craik, Klein & Viswanathan, 2004; Bialystok & Shapero, 2005;) have investigated the performance of bilinguals and monolinguals across the lifespan – children, young adults, middle-aged and older adults - on a diversity of tasks which involve cognitive constructs such as attention. These studies have shown that bilinguals outperformed monolinguals on a variety of cognitive tasks. These findings suggest that the regular use of two different languages can bring positive effects to cognitive functioning.
Many different tasks are used to assess cognitive processing, especially long-term memory systems’ performance of bilingual and monolingual participants. Measures of declarative and procedural memory provide the assessment of participants’ abilities to learn via
these memory systems (Carpenter, 2008). There are tasks that investigate both verbal and non-verbal learning domains both in declarative and procedural memory (e.g. California Verbal Learning Test, Continuous Visual Memory Task, Object/ Picture Naming Task, Artificial Grammar Learning Task, Weather Prediction Task, (Alternating) Serial Reaction Time Task, to mention a few) and these tasks are largely employed in language studies that investigate memory performance both in L1 and in L2 (e.g. Bowden, Gelfand, Sanz & Ullman, 2010; Carpenter, 2008; Chang & Knowlton, 2004; Nemeth, Janacsek, Londe, Ullman, Howard and Howard, Jr., 2010).
To the best of this researcher’s knowledge, no studies have been conducted investigating the relationship (if any) between (1) long-term memory systems performance on behavioral (declarative and procedural memory) tasks developed and performed in participants’ L1 (Brazilian Portuguese) and (2) language proficiency in the L2 (American English). 1.2 The present study
The present study aims at investigating the performance of Portuguese-English bilinguals at two distinct levels of L2 proficiency (low and high proficiency – experimental groups) and of Brazilian Portuguese monolinguals (control group) in four experimental memory tasks designed in Brazilian Portuguese (L1) to assess participants’ declarative and procedural memory. More specifically, the present study attempts at exploring the effect of L2 proficiency on the long-term memory systems of a sample of 40 young adults. The present investigation pursued two research questions:
1. Do young adults, native speakers of Brazilian Portuguese at high proficiency in English as an L2, outperform those at low proficiency and the Brazilian Portuguese monolinguals in the ‘Picture Naming’ and the ‘Artificial Grammar Learning’ linguistic tasks?
2. Do young adults, native speakers of Brazilian Portuguese at high proficiency in English as an L2, outperform those at low proficiency and the Brazilian Portuguese monolinguals in the ‘Picture Recognition’ and the ‘Alternating Serial Reaction Time’ nonlinguistic tasks?
1.3 Significance of the Research
The present study adds to research on the relationship between cognitive processing in L1 and language proficiency in an L2, considering that existing research in Brazil and abroad have explored the construct of proficiency as an important factor in the acquisition and processing of an L2 (e.g. Basso, 2010; Bowden, Gelfand, Sanz & Ullman, 2010; Carpenter, 2008; Luo, Luk & Bialystok, 2009; Morgan-Short; Sanz, Steinhauer & Ullman, 2010; Prebianca, 2009;).
Also, the present study aims at contributing to the research program on SLA and bilingual cognitive processing in two major ways. First, as previously stated, no studies to date, to the best of my knowledge, have been conducted to investigate the relationship between long-term memory systems and L2 proficiency in the language pairing Portuguese-English, more specifically in relation to monolinguals and bilinguals performance in linguistic and nonlinguistic memory tasks. Second, this study uses memory tasks designed in Portuguese and adapted to our Brazilian context, focusing on the investigation of mental processes and memory performance of Brazilian learners of English as an L2.
Lastly, the present study might contribute to the field of psycholinguistics by adding empirical data concerning the nature of language(s) processing and their relationship with the cognitive construct of memory.
1.4 Organization of the thesis
This thesis is organized into five major chapters. Chapter I is the present introductory chapter. Chapter II reviews theoretical and empirical literature found relevant to this investigation. Initially, human memory is explored into its three existing distinctions: episodic and semantic memory, explicit and implicit memory and declarative and procedural memory. Then, the field of Bilingualism is addressed, taking into consideration studies of memory systems in bilinguals; furthermore, the Declarative/Procedural neurocognitive model of language (e.g. Ullman, 2001b) is described. In addition to that, the chapter presents a review on the proficiency factor, focusing on the role of L2 proficiency in cognitive performance.
In chapter III, the objectives, research questions and hypothesis that guide the present study are portrayed. Additionally, it describes the
methodology and general procedures adopted for the study as well as presenting a detailed description of the participants, design, instruments of data collection and analysis.
Chapter IV reports and discusses the results obtained in this study. The descriptive analysis of the performance of low and highly proficient bilinguals and monolinguals on the four memory tasks are presented first, followed by statistical analysis and discussion. Lastly, this chapter readdresses the research questions for the present study.
Chapter V presents and comments the findings and conclusions drawn from this study. Firstly, it portrays a summary of the main findings of the study. In addition, it reports some limitations and mentions suggestions and recommendations for further research. Finally, the chapter includes some pedagogical implications.
CHAPTER II
REVIEW OF LITERATURE
In this chapter, a review of literature related to human memory, bilingualism and language proficiency is presented. It is divided as follows: section 2.1 provides an overview of human memory and its distinctions into episodic/semantic, explicit/ implicit and declarative/ procedural memory (sections 2.1.1, 2.1.2 and 2.1.3, respectively). Section 2.2 is dedicated to general issues of bilingualism, such as memory systems in bilinguals in 2.2.1. Also, this subsection presents the Declarative/ Procedural (DP) Model (e.g. Ullman, 2005), which provides explanation on this neurocognitive model of language (section 2.2.1.1). Finally, section 2.3 is dedicated to language proficiency, followed by studies addressing the role of L2 proficiency in cognitive performance.
2.1 Human Memory
According to Squire and Kandel (2009), “memory is the process by which what is learned persists across time” (p. 2). In the Oxford Handbook of Memory, Tulving (2000) explains that the term memory can designate a number of concepts. Among the more frequently occurring meanings of memory are: (1) memory as neurocognitive capacity to encode, store, and retrieve information; (2) memory as a hypothetical store in which information is held; (3) memory as the information in that store; (4) memory as some property of that information; (5) memory as a componential process of retrieval of that information; (6) memory as an individual’ phenomenal awareness of remembering something (Tulving, 2000, p. 36). To give an account of more concrete illustrations of the various concepts of memory, Tulving (2000) advocates that when one speaks about ‘testing a patient’s memory’ or about ‘profound losses of memory’, one usually has in mind memory in the broad sense of neurocognitive capability of a particular kind, one that is related to but separable at the same time from other cognitive capabilities such as thought and perception. This is the central concept of memory for the purpose of the present study, that is, memory as a neurocognitive capacity to encode, store and retrieve information (Tulving, 2000).
Learning1 and memory are fundamental to human experience (Squire & Kandel, 2009). The study of memory and learning arose from philosophical questions regarding how people come to know things about their world (Bower, 2000). Thus, learning is defined as the primary way we acquire knowledge, and remembering is a primary means by which people support knowledge claims, when, for instance, a witness in court asserts that remembers seeing someone in a given situation with a revolver (Bower, 2000). In this sense, psychology as a discipline developed out of philosophical discussions regarding the nature of the mind and mental life (Bower, 2000).
Until late in the nineteen century, the study of memory was restricted to the domain of philosophy; however, during the twentieth century, the focus of inquiry gradually moved to more experimental studies, initially in psychology, and now biology (Squire & Kandel, 2009). In this millenium, as the authors explain, the questions posed by psychology and biology have begun to converge on common ground (Squire & Kandel, 2009). The combined strength of both disciplines is providing an exciting picture of how the brain learns and remembers; consequently, this scenario has led to a new synthesis of knowledge about learning and memory (Squire & Kandel, 2009).
The study of human memory is one of the most fascinating areas of cognitive science, with research accumulating in various topics as a result of different approaches to this aspect of human cognition (Mota, 1995). Aristotle was perhaps the first to propose a theory of memory, in 384 B.C. and, since then, philosophers have brought forward their insights on the nature of thought and memory (Ashcraft, 1994). Systematic research on memory began with Hermann Ebbinghaus, in a pioneering work on memory for nonsense syllables which took place in the years 1879 and 1880 (Toth, 2000; Xhafaj, 2006). Ebbinghaus initiated the experimental investigation of human memory and the results of this investigation were published firstly in 1885, in a monograph entitled “Memory” and then published again in 1964 (Toth, 2000; Ashcraft, 1994). Ideas such as Ebbinghaus’ (1885/1964) set the stage for modern cognitive conceptions of memory whereby prior experiences are viewed as mental representations, encoded, stored and retrieved in human information-processing system (Toth, 2000).
1 Learning, in the present study, is defined as the process in which new information is acquired
by the nervous system and can be observed through changes in behavior (Purves, Augustine, Fitzpatrick, Hall, LaMantia, MacNamara & White, 2010).
As already mentioned in chapter I (section 1.1) one possible approach towards the understanding of memory is cognitive psychology. In this field of research it is believed that, by observing patterns of behavior, together with private subjective experiences, it will be possible to infer the “mental” events causing such behavior (Gregg, 1986 in Xhafaj, 2006). Considering that mental events take time, one way to infer the workings of the mind is by observing how long a given mental process takes to be completed (Ashcraft, 1994). Following this perspective, Baddeley, in one of his studies (1990), observes that the use of a single term for memory when studying mental processes might suggest that memory is a unitary system, a view that has long been disputed by scholars. Despite Waugh and Norman (e.g. Gregg, 1986) having coined the terms Primary and Secondary memory, William James was the first to use them, in 1890, to define that Primary memory is the memory immediately available, the one we are aware of, and Secondary memory is a larger one, usually hidden or passive, which holds past experiences (Gregg, 1986). An interesting fact is that later, in the 1950s and 1960s, when the first serious models of information-processing were put forward, these same two kinds of memory were included (Ashcraft, 1994).
Much later, in the 1990s, Baddeley claimed that there was strong empirical evidence against a unitary view of memory. In 2002, he stated again that the concept of human memory as a unitary faculty began to be seriously eroded in the 1960s, with a proposal of the fractionation of memory into long-term memory (LTM) and short-term memory (STM) (Baddeley, 2002)2. Researchers (e.g. Purves et al.,2010; Baddeley, 2002) explain that human memory can be categorized according to the time in which it is effective in our minds. Details concerning this division are still part of a hot debate among psychologists and neurobiologists; however, three categories are largely accepted (Purves et al., 2010).
The first is immediate memory, which is our daily capacity to maintain in conscience, from fractions of seconds to a few seconds, our ongoing experiences (e.g. what you just read in this paragraph) (Purves et al., 2010). The second category of memory is working memory, which is the capacity of maintain and manipulate information in conscience from 2 The most influential two-component memory model was that of Atkinson and Shiffrin (1968),
who proposed that information came in from the environment into a temporary short-term storage system which served as an antechamber to the more durable long-term memory (Baddeley, 2003). In their model, “the temporary system also served as a working memory, a workspace necessary not only for long-term learning, but also for many other complex activities such as reasoning and comprehension” (Atkinson and Shiffrin, 1968 in Baddeley, 2003).
seconds to a few minutes, while it is used to achieve a given behavioral goal (e.g. when you lose your car keys at your home; because of your working memory, you do not search for it in repeated places) (Purves et al., 2010). Finally, the third category of memory is long-term memory, which concerns the retention of information in a more permanent manner, for days, weeks, years or even a lifetime (Purves et al., 2010). The authors also advocate that part of the information held in the immediate memory and in the working memory is stored as long-term memory, although most of this registration is forgotten, as a natural process of non-oppression of our encephalon with huge amounts of information (Purves et al., 2010). The different types of memory have their own particular mode of operation, but they will certainly cooperate in the process of memorization.
As explained by Baddeley (1992a), researchers have tended to conceptualize this system along two main lines of study (Mota, 1995). In the first one, long-term memory is divided into episodic and
semantic memory, a distinction first proposed by Tulving (e.g. 1985). In
the second one, the system is divided into declarative and procedural
memory, terms adopted after the study by Anderson (1983 in Mota,
1995). There is a third line of research referring to long-term memory. In this line, long-term memory is subdivided into implicit and explicit
memory, terms employed by neuropsychologists such as Schacter, in a
study from the late 1980s (1987).3
From the types of memory mentioned above, long-term memory is the category explored in the current study. In general terms, it is through this category that our knowledge about the world is acquired from our experiences and maintained in our minds (e.g. Squire & Kandel, 2009). Therefore, memory holds our record of personal experience, and it is a powerful force to our unique ability to communicate (Squire & Kandel, 2009). Hence, memory is central to many aspects of human experience, such as psychological and emotional issues, as a result of experiences that have been coded in it (Squire & Kandel, 2009). The localization of memory storage is part of a tradition that attempts to address the following issue: Can any mental processes be localized to a specific region or a combination of regions in the human brain? (Squire & Kandel, 2009).
Recent findings in the cognitive neuroscience of memory (e.g. Eichenbaum, 2002) refer to memory as encoded within the cerebral 3 Further explanations on the long-term memory distinctions will be fully detailed in sections
cortex in two general ways, each of which involving a modification of the normal sensory processing function of the cells in these specific areas (Eichenbaum, 2002). Firstly, Eichenbaum (2002) states, memory is reflected in the capacity of cortical cells to shift or modulate the responses evoked by the stimuli that drive them. Second, the author stresses, “memory is encoded in the capacity of cells to sustain or reactivate their normal sensory responses in the absence of the stimulus ordinarily required to evoke the representation” (Eichenbaum, 2002, p. 192). These observations emphasize the fundamental theme that memory should be conceived as intimately intertwined with information processing in the cortex, in which “memory” and “information processing” are indistinguishable (Eichenbaum, 2002). One interpretation of this view is that memory is related to the plastic properties of specific cortical information processing; in this sense, the mechanisms of the cerebral cortex – divided into four major regions or lobes4 - involve a combination of information processing and memory to constitute neural networks that contain the structure of our knowledge about the world (Eichenbaum, 2002; Squire & Kandel, 2009). To account for such findings, biological approaches have recently joined with those of systems neuroscience and with cognitive psychology; this perspective forms a unified science that has proven to be fascinating from a molecular and also behavioral point of view (Squire & Kandel, 2009). The partnership between these once independent areas of study is leading to a new synthesis of knowledge about memory and the brain; these fields together are explaining issues on how nerve cells work together in neural circuits, how learning processes and memory systems are organized, and how they operate (Squire & Kandel, 2009). Squire & Kandel (2009) also point out that investigations of brain systems and behavior are providing a road map that identifies components of memory, areas of the brain where these components can be studied in detail, and also nerve cells in a particular neural circuit related to a particular form of memory in mind.
As previously explained, long-term memory is the one of the focus of the present investigation. It can be explored into three distinctions: episodic/semantic, explicit and implicit and declarative and procedural memory. In the next section, the distinction episodic-semantic memory will be explored.
4 The cerebral cortex is divided into frontal, temporal, parietal and occipital lobes, in which the
2.1.1 Episodic/Semantic memory distinction
According to Tulving (1972), episodic and semantic memory are two information processing systems that (a) selectively receive information from perceptual systems (Gibson, 1966 in Tulving, 1972) or other cognitive systems, (b) retain various aspects of that information, and (c) upon instructions transmit specific retained information to other systems, including those responsible for translating this into behavior and conscious awareness. Tulving (1972) explains that these two systems differ from one another in terms of (a) the nature of stored information, (b) autobiographical versus cognitive reference, and (c) conditions and consequences of retrieval, and probably in terms of (d) their vulnerability to interference resulting in transformation and erasure of stored information. Besides, the author complements with another difference: their dependence upon each other (Tulving, 1972).
Episodic memory receives and stores information about temporally dated episodes or events, and temporal-spatial relations among these events (Tulving, 1972). Tulving (1972) observes that a perceptual event can be stored in the episodic system uniquely in terms of its perceptible properties or attributes, and it is always stored in terms of autobiographical reference to the already existing content of the episodic memory store. In contrast, semantic memory is the memory necessary for the use of language (Tulving, 1972). Is it a mental thesaurus, that is, an organized knowledge a person possesses about words and other verbal symbols, their meaning and referents and about relations among them; semantic memory does not register perceptible properties of inputs, but rather cognitive referents of input signals (Tulving, 1972). The semantic system, according to Tulving (1972) is probably much less susceptible to involuntary transformation and loss of information than the episodic system.
Both episodic and semantic memories are part of declarative memory. As explained by Squire (2004), declarative memory is the kind of memory that is meant when the term “memory” is used in everyday language. It is related to the capacity for conscious recollection about facts and events (e.g. Cohen & Squire, 1980; Ullman, 2001a; 2005), and is the kind of memory that is impaired in amnesia (e.g. Baddeley, 2002; Cohen & Squire, 1980; Schacter, 1992; Squire, 1992) and dependent on structures in the medial temporal lobe and midline diencephalon (Squire, 2004). As previously stated, declarative memory can be divided into semantic memory (facts about the world) and episodic memory (the capacity to
re-experience an event in the context in which it originally occurred (Cohen & Squire, 1980; Tulving, 1983 in Squire, 2004). Moreover, episodic memory requires the participation of brain systems in addition to those that support semantic memory, for example, the frontal lobes (Shimamura & Squire, 1987 in Squire, 2004).
As pointed out by Tulving (1983 in Bower, 2000) the episodic and semantic memory systems were contrasted in terms of their conditions and consequences of retrieval, nature of stored information, vulnerability to interference, and interdependence. Bower (2000) explains that this hypothesis has led to much discussion in the literature; critics argue that although the two classes of memories clearly differ in their contents, strengths, and specific time-place contextual references, the two classes are otherwise similar in their properties (Bower, 2000). The discussion has continued over the years. Recent developments have proposed use of brain neuroimaging data gathered during episodic versus semantic retrieval tasks, in an attempt to obtain discriminating evidence for the brain-basis for the distinction (e.g. Bower, 2000; Buckner, 1996). 2.1.2 Explicit/Implicit memory distinction
One important issue that has emerged from recent studies of learning and memory concerns the possibility that information can be learned implicitly and independently of awareness (Knowlton & Squire, 1996). Considering this assumption, different aspects of memory - explicit and implicit memory5 – will be reviewed in this section. According to Schacter (1987), “implicit memory is revealed when previous experiences facilitate performance on a task that does not require conscious or intentional recollection of those experiences; explicit memory is revealed when performance on a task requires conscious recollection of previous experiences” (p. 501). Dornyei (2009) states that these conceptual areas (first explicit-implicit memory, and then the closely related declarative-procedural paradigm) dominate contemporary memory research, each having its own substantial body of literature. These paradigms appear to cover very similar ground and the corresponding terms are often used 5 The explicit-implicit dichotomy appears in many forms in research on language acquisition,
and it has been applied to SLA as well. The gist of the contrast, according to Dornyei (2009) is clear: ‘explicit’ has something to do with consciousness, while ‘implicit’ is associated with unconscious, automatic, or indirect processes. The explicit-implicit dichotomy is applied to three different concepts in the literature – learning, knowledge and memory, and it is only very rarely explained how these are interconnected (Dornyei, 2009).
interchangeably (Dornyei, 2009). Empirical research on implicit learning falls largely into three categories: artificial grammars, sequence learning, and control of complex systems (DeKeyser, 2003). The oldest paradigm, and the one that continues to generate most research, is artificial grammar learning (AGL). In this paradigm, participants are typically able to discriminate the grammatical strings with above-chance accuracy despite believing they are guessing or using intuition and despite being unable to verbalise the rules of grammar (e.g. Scott & Dienes, 2010). From the first experiment originally proposed by Reber (1967), (in which the author states that the ability to discriminate grammatical strings resulted from the implicit acquisition of regularities encountered during learning) to subsequent experiments (e.g. Reber, 1976), the controversy they generated led to an industry of artificial grammar studies of increasing complexity and sophistication (e.g. Chang & Knowlton, 2004; Dienes, Broadbent & Berry, 1991; Knowlton & Squire, 1994; 1996; Scott & Dienes, 2010).
Researchers (e.g. Butler & Berry, 2001 Dornyei, 2009; Paradis, 2004; Perrig, 2001) have explored explicit and implicit dichotomy by observing memory as a psychological term, conceptualized in terms of retrieval rather than internal representations or structure. Because of that, it becomes clear why ‘memory tasks’ assume a special importance; after all, retrieval can be operationalized only through these tasks (e.g. Perrig, 2001). Perrig (2001) observes that ‘implicit memory’ refers to memory effects that can be shown by implicit tasks that, in contrast to explicit tasks, do not instruct the subjects to remember what happened in the past. In this, the author explains, the terms ‘implicit’ and explicit’ refer to different tasks, distinguished operationally by the instructions given to subjects at test (Perrig, 2001).
In a study carried out by Dienes, Broadbent and Berry (1991), the authors examined the claim for distinct implicit and explicit learning modes in the artificial grammar learning task (Reber, 1967; 19896). Artificial grammar learning is a paradigm that has been extensively used to investigate the acquisition of implicit knowledge (e.g. Carpenter, 2008; Chang & Knowlton, 2004; Knowlton & Squire, 1996; Reber, 1967, 1989; Reber & Allen, 1978). In this paradigm, subjects typically memorize strings of letters that appear arbitrary but are actually generated by a set of 6 Arthur Reber, the pioneer of implicit learning research, defined implicit learning as “a primitive
process of apprehending structure by attending to frequency cues” as opposed to “a more explicit process whereby various mnemonics, heuristics, and strategies are engaged to induce a representational system (1976, p.93).
rules in the form of a finite-state grammar (e.g. DeKeyser, 2003; Dienes et al., 1991). Subjects never get to see the rules, and are generally not aware of the rules after being exposed to a set of exemplar strings; yet, they perform above chance when they are unexpectedly asked to classify new strings into those that conform to the structure of the exemplars and those that do not (DeKeyser, 2003).
In Dienes et al’s study (1991), 40 healthy young adults initially attempted to memorize strings of letters and then classified new grammatical or nongrammatical strings. According to these researchers, results have shown that subjects’ assessment of isolated parts of strings was sufficient to account for their classification performance. Subjects’ typical classification performance – about 65% - indicated that these participants have acquired substantial knowledge about the artificial grammar (Dienes et al., 1991).
Knowlton and Squire (1996) found evidence of implicit learning in unhealthy subjects. In this investigation, the contributions of exemplar-specific and abstract knowledge to artificial grammar learning were examined in amnesic patients and controls (Knowlton & Squire, 1996). In Experiment 1, grammatical rule adherence and chunk strength exerted separate effects on grammaticality judgments (consider ‘chunk strength’ as the number of times the chunks – bigrams or trigrams of letters – appeared in the training items). Results demonstrated that amnesic patients exhibited intact classification performance, showing the same pattern of results as controls (Knowlton & Squire, 1996). In Experiment 2, amnesic patients showed impaired declarative memory for chunks; for Experiment 3, the results indicated that both amnesic patients and controls exhibited transfer when tested with a letter set different than the one used for training, although performance was better when the same letters were used at training and test (Knowlton & Squire, 1996). Overall results suggest that individuals learn both abstract information about training items and exemplar-specific information about chunk strength and that both types of learning occur independently of participants’ declarative memory (Knowlton & Squire, 1996).
More recent work conducted by Chang & Knowlton (2004) investigated whether exemplar-specific knowledge acquired in the artificial grammar learning task is based on the visual features of the exemplars, that is, when a change in the font and case occurred between study and test. Sixty undergraduate students (44 women and 16 men) took part in the experiments. Results have shown that there was no
effect on sensitivity to grammatical rules in classification judgments (Chang & Knowlton, 2004). Nevertheless, such a change in font and case virtually eliminated sensitivity to training frequencies of letter bigrams and trigrams (chunk strength) in classification judgments (Chang & Knowlton, 2004). Also, performance on a secondary task during study eliminated this font sensitivity and generally reduced the contribution of chunk strength knowledge (Chang & Knowlton, 2004). The findings are consistent with the notion that perceptual fluency makes a contribution to artificial grammar learning judgments (Chang & Knowlton, 2004).
It is commonly held that implicit knowledge expresses itself as fluency (Scott & Dienes, 2010). Also, there is substantial evidence in literature that the knowledge acquired in implicit learning – especially of artificial grammars – is expressed largely as familiarity, defined as the subjective feeling of oldness elicited by a stimulus (e.g. Scott & Dienes, 2008). A question that arises is related to the basis of that familiarity. In a 2010 study, Scott and Dienes used a perceptual clarification task to examine the relationship between perceptual processing fluency, subjective familiarity, and grammaticality judgments through artificial grammar learning. Four experiments with young adults explored the effects of naturally occurring differences and manipulated differences in perceptual fluency, in which decisions were based on a brief exposure to test-strings or normal exposure. According to Scott and Dienes (2010), when perceptual fluency was not manipulated, it was weakly related to familiarity and grammaticality judgments, but unrelated to grammatical status and hence not a source of accuracy. Counterbalanced grammatical and ungrammatical strings did not differ in perceptual fluency but differed in subjective familiarity (Scott & Dienes, 2010). On the other hand, when fluency was manipulated, faster clarifying strings were rated as more familiar and were more often endorsed as grammatical but only when exposure was brief. Results suggest that subjective familiarity derived from a source other than perceptual fluency, is the primary basis for accuracy in artificial grammar learning.
The next section will address the declarative-procedural memory dichotomy.
2.1.3 The Declarative/Procedural memory distinction
Humans possess at least two different systems for storing information. These systems are usually designated as declarative and
nondeclarative memory systems (Purves et al., 2010). Stimulated
by neuropsychological studies showing that brain- damaged patients sometimes display normal performance on certain types of memory tasks despite exhibiting severe impairments on others, and by experimental demonstrations in healthy populations that performance on different types of memory tasks can be dissociated from one another, contemporary researchers have postulated distinctions among a number of forms of memory or memory systems (Schacter, Wagner & Buckner, 2000). These distinctions include, but are not limited to, episodic and semantic memory (e.g. Tulving, 1972, 1983), implicit and explicit memory (e.g. Dornyei, 2009; Schacter, 1987) and also declarative and nondeclarative (e.g. Squire, 1992; Squire & Kandel, 2009) or procedural memory7 (e.g. Cohen & Eichenbaum, 1993; Eichenbaum, 2002; Ullman, 2005).
According to Dornyei (2009), the declarative-procedural distinction is used with regard to knowledge and the memory that stores that knowledge. Declarative knowledge is frequently taken as a synonym for explicit knowledge and procedural knowledge for implicit knowledge. As observed by Carlson (2003, p. 38), “declarative knowledge is knowledge that can be explicitly expressed (“declared”) or consulted, whereas procedural knowledge (‘knowing how’) can only be performed”. One difference in emphasis between the terms ‘implicit’ and ‘procedural’ is that procedural knowledge/ memory is usually used in the context of skill learning and skill performance rather than rule learning (Dornyei, 2009).
Bear, Connors & Paradiso (2008) explain that throughout our lives, we learn many facts (e.g., Bangkok is the capital of Thailand); we also store information about events in our daily lives, such as “I ate cereal for breakfast this morning” or “I had an annoying Chemistry class yesterday”. This memory system for facts and events is the declarative memory, that is, what we usually refer to when mentioning the word memory in its daily use (Bear et al., 2008). In a general sense, declarative memories are available to conscience, as opposed to nondeclarative memory. Another difference observed by the authors is that declarative memories are frequently easy to compose and also easy to forget. In contrast, the formation of nondeclarative memories tends to require repetition and practice during a longer period, but these memories have a lower probability of being forgotten (Bear et al., 2008). Nondeclarative memories can be focused 7 The terms nondeclarative and procedural memory are brought together in this section to
on procedural memory, or a memory for procedures. This is the memory system for abilities, habits and behavior, and it is related to information such as learning how to play the piano, to play soccer or to drive a car, because somehow this information is stored in our encephalon as a direct result from experience (Bear et al., 2008).
One important aspect of both declarative and procedural memory is that neuroanatomical studies have been successful in identifying the brain areas where each type of memory resides (Dornyei, 2009). Declarative memory appears to be primarily located in the medial temporal lobe, including the hippocampus, whereas procedural memory is usually associated with a network of more diffuse brain structures rooted in the frontal/basal ganglia circuits (e.g. Ullman, 2004). An important contribution from these studies is that they clearly dissociate the two systems from each other.
According to Paradis (2004), the implicit competence which underlies the performance of motor and cognitive skills is said to be procedural because it relates to internalized procedures, genuine behavior programs, which eventually contribute to the automatic performance of the task. Thus procedural memory contrasts with declarative memory, which subserves everything that can be represented at the conscious level, i.e., memory of specific, consciously experienced events (e.g., the recollection of what happened on a particular occasion, and what psychologists call semantic memory, i.e., the individual’s general encyclopedic knowledge (i.e., the knowledge that an event too place, whether or not one was present), including the knowledge of the meaning of words (Paradis, 2004). Paradis (2004) yet states that the procedural/declarative memory dimension is a crucial element that determines the performance in the appropriation, use and loss of languages.
The declarative-procedural dichotomy is closely associated with the work of cognitive psychologist John Anderson. This dichotomy comprises an integral part of Anderson’s ‘ACT-R’ theory. This acronym stands for Adaptive Control of Thought-Rational, and is an evolving conceptualization of the overall architecture of human cognition by John Anderson and his colleagues (Anderson et al., 2004). ACT-R has grown out of Anderson’s earlier ACT theory, which represented a cognitive psychological approach based on the distinction between declarative and procedural memory since its inception in the mid-1970s (Dornyei, 2009).
Following Anderson’ distinction of declarative and procedural memory, Michael Ullman and his collaborators have been pursuing
a unique, focused agenda to investigate the neurocognition of both L1 and L2, using neuroimaging techniques. Over the past years, Ullman has proposed a theory that applies the declarative-procedural distinction to L2 knowledge (e.g. Ullman, 2001a; 2004; 2005). According to Ullman (2005), few studies were conducted in order to address the specific neural substrates of second language and the relations between its neural, cognitive, and computational underpinnings. In this line, the author proposes a neurocognitive model - declarative/ procedural (DP) model - (Ullman, 2001a; 2001b; 2001c; 2004; 2005) that is meant to complete these theoretical gaps concerning the context of both first and second languages and to promote a broader understanding of the mind and the brain (e.g. Ullman, 2005).
In the perspective addressed by this model, both first and second languages are acquired and processed by two well-studied brain systems (declarative and procedural memory) that underlie the use of language (Ullman, 2001b). In the L1, the model poses that the mental lexicon and the mental grammar are posited to rely on one of the two memory systems. On the one hand, the memorization, storage and processing of the sound-meaning pairings of lexical memory are subserved by declarative memory, a brain memory system that is rooted in medial temporal lobe regions (e.g. the hippocampus), which are connected extensively with temporal and parietal neocortical regions (Suzuki and Amaral, 1994 in Ullman, 2005); this system may be peculiarly important for learning arbitrary relations (such as the fact that Paris is the capital of France) and it is implicated in the learning, representation and use about facts (semantic knowledge) and events (episodic knowledge) (Ullman (2001b; 2005).8
The knowledge learned in declarative memory is partly explicit, that is, available to conscious awareness (Ullman, 2005). On the other hand, Ullman (2001b, 2005) states that the learning, representation, and processing of aspects and rules of grammar depend upon procedural memory, a brain memory system that is rooted in left frontal/basal-ganglia structures, and is implicated in the learning and use of motor and cognitive skills and habits, especially involving sequences. Neither the learning nor the remembering of these procedures seems to be accessible to conscious memory; thus, this system is frequently referred to as an implicit memory system (Ullman, 2005). These rules of grammar processed by this system constrain how lexical forms combine to make complex representations, 8 The Declarative Procedural Model of language and its predictions are further discussed in
and allow us to interpret the meanings of morphologically simple and complex forms (Ullman, 2005).
In the next section, bilingualism will be addressed, followed by aspects of memory systems in bilinguals in section 2.2.1 and the declarative-procedural model (section 2.2.1.1).
2.2 Bilingualism
There are a number of experiences that effectively influence cognitive performance. One of these experiences is that of being bilingual. Paradis (2004) suggests that there is no consensus about what a bilingual individual is. In other words, a monolithic concept does not exist because defining bilinguals can involve a wide category of concepts; because of that, defining a bilingual is a difficult task. In any study of bilingualism, one needs to be aware that bilinguals do not form a homogeneous group. As a matter of fact, a consensus does not even exist as to what constitutes a bilingual (Paradis, 2004). The dictionary definition of a bilingual is usually of a “person who knows or uses two languages”. However, this definition leaves open for interpretation what it means to know a language and also to what extent it must be used to define one as bilingual (Paradis, 2004). Consequently, some authors consider their subjects to be bilingual as long as they have some reading knowledge of a language other than their native language (e.g., Macnamara, 1969), while others insist that a bilingual must understand and speak each language like a native in all modalities of use, all domains of discourse, and all sociolinguistic registers; in sum, in all levels of formality and informality (e.g. Thiery, 1976).
According to Bialystok (2010), “the cognitive and linguistic processes involved in the acquisition and use of two languages are systematically different from those processes engaged in monolingual language use, leading to detectable changes in language and cognitive outcomes for bilinguals” (p. 1). Another evidence for the influence of bilingualism was found by Mechelli et al. (2004), in which early bilinguals and people who have greater proficiency in the L2 have increased density in the brain, shown in the left inferior parietal cortex, a region that is responsible for vocabulary acquisition in monolinguals and bilinguals. In this line, Bialystok (2009) explains that the crucial aspect for fluent bilinguals’ experience, which often use both languages, is the fact that when one is in use, both are active and available (e.g. Kaushanskaya & Marian, 2007). Because of this, bilinguals need to control attention to
